阅读说明：本技术 一种TiO2/NaNiF6复合光催化剂及其制备方法 (TiO22/NaNiF6Composite photocatalyst and preparation method thereof ) 是由 赵文武 郁建元 刘进强 曹紫玉 宋梦晗 王秀文 郝斌 刘剑 于 2021-08-19 设计创作，主要内容包括：本发明公开了一种TiO-(2)/NaNiF-(6)复合光催化剂及制备方法,属于光催化技术领域,本申请的TiO-(2)/NaNiF-(6)复合光催化剂制备方法为将铁尾矿砂中加入NaOH进行熔融处理制备得到铁尾矿溶液,铁尾矿溶液和氟钛酸铵进行水热反应制得。本申请制得的TiO-(2)/NaNiF-(6)复合光催化剂具有优良的光催化性能,并且充分利用了固体废物铁尾矿砂,变废为宝。(The invention discloses a TiO2 2 /NaNiF 6 A composite photocatalyst and a preparation method thereof belong to the technical field of photocatalysis, and the TiO of the application 2 /NaNiF 6 The preparation method of the composite photocatalyst comprises the steps of adding NaOH into iron tailing sand for melting treatment to prepare an iron tailing solution, and carrying out water treatment on the iron tailing solution and ammonium fluotitanateAnd (3) carrying out thermal reaction. TiO produced herein 2 /NaNiF 6 The composite photocatalyst has excellent photocatalytic performance, and the solid waste iron tailing sand is fully utilized, so that waste is changed into valuable.)

1. TiO2₂/NaNiF₆The composite photocatalyst is characterized in that: the photocatalyst is prepared by carrying out hydrothermal reaction on iron tailing sand after alkali treatment and ammonium fluotitanate.

2. TiO2₂/NaNiF₆Process for preparing composite photocatalystCharacterized by comprising the following steps:

s1: pretreatment: firing a nickel crucible at high temperature, cooling for later use, drying iron tailing sand, grinding and sieving;

s2: preparing an iron tailing solution: accurately weighing the iron tailing sand in the step S1, placing the iron tailing sand in a nickel crucible, firing, cooling, adding NaOH particles, mixing uniformly, heating and melting, taking out and cooling, alternately adding a small amount of hot water and dilute nitric acid to leach out a melt, pouring the melt into a beaker, dropwise adding the dilute nitric acid to clarify an iron tailing solution, transferring the iron tailing solution into a volumetric flask, and adding deionized water to a constant volume;

s3: adding ammonium fluotitanate into a beaker, adding a small amount of deionized water, stirring and dissolving, taking the iron tailing solution obtained in the step S2, pouring the ammonium fluotitanate solution into the iron tailing solution, stirring, dropwise adding a NaOH solution to adjust the pH value, stopping stirring, pouring into a hydrothermal kettle, and heating the hydrothermal kettle;

s4: taking out the hydrothermal kettle, filtering the solution in the hydrothermal kettle, and then washing and filtering for three times to obtain powder;

s5: adding deionized water into the powder, and centrifuging after ultrasonic treatment for 4 hours; repeating the steps for three times, and putting the obtained powder into a drying oven to be dried for 10 hours;

s6: and drying the powder, grinding in a mortar, and sealing.

3. A TiO according to claim 2₂/NaNiF₆The preparation method of the composite photocatalyst is characterized by comprising the following steps: the concentration of the iron tailing solution prepared in the step S2 is 2mg/mL, and the mass ratio of the iron tailing sand to the NaOH particles is 1:6-1: 10.

4. A TiO according to claim 2₂/NaNiF₆The preparation method of the composite photocatalyst is characterized by comprising the following steps: in the step S3, the adding proportion of the ammonium fluotitanate and the iron tailing solution is 3-5 g: 200mL, and a fill ratio in the hydrothermal reactor was 60%.

5. A TiO according to claim 2₂/NaNiF₆Preparation method of composite photocatalystThe method is characterized in that: in the step S1, the firing temperature of the nickel crucible is 850-900 ℃, the firing is 3-5 min, the drying temperature of the iron tailings is 105-110 ℃, and the drying is carried out for 2 h.

6. A TiO according to claim 2₂/NaNiF₆The preparation method of the composite photocatalyst is characterized by comprising the following steps: in the step S2, the burning temperature of the iron tailings is 850-900 ℃, the burning is performed for 3-5 min, and NaOH particles are added and then heated and melted for 10 min.

7. A TiO according to claim 2₂/NaNiF₆The preparation method of the composite photocatalyst is characterized by comprising the following steps: in the step S3, the concentration of the NaOH solution is 4mol/L, the pH value is adjusted to 8-9, the heating temperature of the hydrothermal kettle is 170-190 ℃, and the heating time is 10-12 h.

8. A TiO according to claim 2₂/NaNiF₆The preparation method of the composite photocatalyst is characterized by comprising the following steps: in step S4, the first two washing solutions are deionized water, and the third washing solution is absolute ethanol.

9. A TiO according to claim 2₂/NaNiF₆The preparation method of the composite photocatalyst is characterized by comprising the following steps: in the step S5, the drying temperature is 70-90 ℃.

10. A TiO according to claim 2₂/NaNiF₆The preparation method of the composite photocatalyst is characterized by comprising the following steps: the filtering sieve used in the sieving step in the step S1 is 200 mesh.

Technical Field

The invention belongs to the technical field of photocatalysis, and relates to TiO₂/NaNiF₆A composite photocatalyst and a preparation method thereof.

Background

Environmental problems such as global warming, ozone depletion, and the disappearance of biodiversity have seriously threatened the continued proliferation and survival of human beings. Among the various environmental pollutants, the most common, major and most influential is chemical pollution.

The photocatalyst is also called a photocatalyst, and is a generic name of a semiconductor material having a photocatalytic function represented by nano-sized titanium dioxide. The semiconductor photocatalysis technology is used as a novel environmental pollutant reduction technology, and utilizes the characteristics that the surface of a semiconductor oxide material can be activated under illumination, organic matters are effectively oxidized and decomposed, heavy metal ions are reduced, and the like, so that the semiconductor photocatalysis technology is antibacterial and removes peculiar smell. A typical photocatalytic material is titanium dioxide, which generates a substance having a strong oxidizing property (e.g., hydroxyl radical, oxygen, etc.) under light irradiation, and is useful for decomposing organic compounds, partially inorganic compounds, bacteria, viruses, etc. In daily life, the photocatalyst can effectively degrade toxic and harmful gases in the air, such as formaldehyde and the like, and efficiently purify the air; meanwhile, various bacteria can be effectively killed, and toxin released by the bacteria or fungi can be decomposed and harmlessly treated.

The main mineral components of iron tailings in different domestic areas and typical foreign iron tailings are quartz, calcite, montmorillonite, dolomite, hematite, feldspar and the like, so that the main components of the iron tailing sand comprise elements such as silicon, aluminum, iron, calcium, magnesium and the like. According to the composition of the iron tailing sand, the iron tailing sand contains various valuable metals, and the characteristic enables the iron tailing sand to be widely applied. If the solid waste iron tailing sand can be introduced into the field of photocatalysis to be recycled, considerable economic value can be created, waste can be changed into valuable, and a new way is provided for recycling industrial waste.

Disclosure of Invention

The invention provides a TiO₂/NaNiF₆The composite photocatalyst fully utilizes iron tailing sand as a raw material, the preparation process is simple, and the prepared TiO is₂/NaNiF₆The composite photocatalyst has stable performance and excellent photocatalytic performance.

In order to achieve the purpose, the technical scheme of the invention is as follows:

a TiO2/NaNiF6 composite photocatalyst is prepared by carrying out hydrothermal reaction on iron tailing sand and ammonium fluotitanate after alkali treatment.

The preparation method of the TiO2/NaNiF6 composite photocatalyst comprises the following steps:

s1: pretreatment: firing a nickel crucible at high temperature, cooling for later use, drying iron tailing sand, grinding and sieving;

s2: preparing an iron tailing solution: accurately weighing the iron tailing sand in the step S1, placing the iron tailing sand in a nickel crucible, firing, cooling, adding NaOH particles, mixing uniformly, heating and melting, taking out and cooling, alternately adding a small amount of hot water and dilute nitric acid to leach out a melt, pouring the melt into a beaker, dropwise adding the dilute nitric acid to clarify an iron tailing solution, transferring the iron tailing solution into a volumetric flask, and adding deionized water to a constant volume;

s3: adding ammonium fluotitanate into a beaker, adding a small amount of deionized water, stirring and dissolving, taking the iron tailing solution obtained in the step S2, pouring the ammonium fluotitanate solution into the iron tailing solution, stirring, dropwise adding a NaOH solution to adjust the pH value, stopping stirring, pouring into a hydrothermal kettle, and heating the hydrothermal kettle;

s4: taking out the hydrothermal kettle, filtering the solution in the hydrothermal kettle, and then washing and filtering for three times to obtain powder;

s5: adding deionized water into the powder, and centrifuging after ultrasonic treatment for 4 hours; repeating the steps for three times, and putting the obtained powder into a drying oven to be dried for 10 hours;

s6: and drying the powder, grinding in a mortar, and sealing.

The technical scheme of the invention is further improved as follows: the concentration of the iron tailing solution prepared in the step S2 is 2mg/mL, and the mass ratio of the iron tailing sand to the NaOH particles is 1:6-1: 10.

The technical scheme of the invention is further improved as follows: in the step S3, the adding proportion of the ammonium fluotitanate and the iron tailing solution is 3-5 g: 200mL, and a fill ratio in the hydrothermal reactor was 60%.

The technical scheme of the invention is further improved as follows: in the step S1, the firing temperature of the nickel crucible is 850-900 ℃, the firing is 3-5 min, the drying temperature of the iron tailings is 105-110 ℃, and the drying is carried out for 2 h.

The technical scheme of the invention is further improved as follows: in the step S2, the burning temperature of the iron tailings is 850-900 ℃, the burning is performed for 3-5 min, and NaOH particles are added and then heated and melted for 10 min.

The technical scheme of the invention is further improved as follows: in the step S3, the concentration of the NaOH solution is 4mol/L, the pH value is adjusted to 8-9, the heating temperature of the hydrothermal kettle is 170-190 ℃, and the heating time is 10-12 h.

The technical scheme of the invention is further improved as follows: in step S4, the first two washing solutions are deionized water, and the third washing solution is absolute ethanol.

The technical scheme of the invention is further improved as follows: in the step S5, the drying temperature is 70-90 ℃.

The technical scheme of the invention is further improved as follows: the filtering sieve used in the sieving step in the step S1 is 200 mesh.

Due to the adoption of the technical scheme, the invention has the following technical effects:

the application introduces the solid waste iron tailings sand into the field of photocatalysis to prepare TiO₂/NaNiF₆The composite photocatalyst has simple preparation process, the prepared product has good photocatalytic performance, the iron tailing sand which is an industrial waste is fully utilized, the resource utilization is realized, and the waste is changed into valuable。

Drawings

Fig. 1 is an XRD detection chart of the powder prepared in the examples of the present application.

Detailed Description

The technical solution of the present invention will be described in detail with reference to the specific embodiments.

Experimental equipment:

electric heating constant temperature air blast drying oven DHG-9030AD

Circulating water type vacuum pump SHD-III

Hydrothermal kettle 50mL

Example 1

The early-stage treatment work comprises the following steps: drying the iron tailings at 105-110 ℃ for 2h, grinding, sieving with a 200-mesh sieve, burning a nickel crucible at 850-900 ℃ for 3-4 min, and cooling for later use.

Preparing an iron tailing solution: accurately weighing about 0.5g of the treated iron tailing sand, placing the iron tailing sand in a nickel crucible, and firing the iron tailing sand for 3-5 min at the temperature of 850-900 ℃. Cooling a crucible, adding 5g of solid sodium hydroxide particles, uniformly mixing iron tailing sand and sodium hydroxide by using a fine glass rod, covering a crucible cover, melting at the temperature of 750-850 ℃ for 10min, taking out, cooling, leaching the melt by using a small amount of hot water and dilute nitric acid alternately, pouring into a 500mL beaker, and washing the crucible by using a small amount of dilute nitric acid and water. The iron tailing solution was clarified by adding 20 ml nitric acid dropwise to a 500ml beaker, and then poured into a 250 ml volumetric flask and adding deionized water to the scale mark.

Hydrothermal method for preparing TiO₂/NaNiF₆Composite photocatalyst

0.3g of ammonium fluotitanate was added to a beaker, a small amount of deionized water was added, and the beaker was placed on a rotor and placed on a magnetic stirrer to melt it. And adding 20 ml of iron tailing solution into another beaker, pouring the ammonium fluotitanate solution into the beaker containing the iron tailing solution, adding sodium hydroxide solution to adjust the pH value, starting adding one drop when light yellow floccules appear, adjusting the pH value of the solution to be 8, taking out a rotor, keeping the solution at 30 ml, and pouring the solution into a hydrothermal kettle if deionized water is not added sufficiently for complete supplement. The hydrothermal kettle was then heated in a forced air drying oven at 180 ℃ for 10 hours.

Filtering, washing and suction-filtering the solution in the hydrothermal kettle for three times, using deionized water for the first two times and using absolute ethyl alcohol for the last time, putting the obtained powder in a beaker, adding 100mL of deionized water, performing ultrasonic treatment for 4 hours, and then centrifuging; this was repeated three times and the powder was dried in a forced air oven at 80 ℃ for 10 h. Taking out after drying, grinding in a mortar, taking out and placing in a sealed bag.

Example 2

The early-stage treatment work comprises the following steps: drying the iron tailings at 105-110 ℃ for 2h, grinding, sieving with a 200-mesh sieve, burning the iron tailings at 850-900 ℃ for 3-4 min, and cooling for later use.

Preparing an iron tailing solution: accurately weighing about 0.5g of the treated iron tailing sand, placing the iron tailing sand in a nickel crucible, and firing the iron tailing sand for 3-5 min at the temperature of 850-900 ℃. Cooling the crucible, adding 3g of solid sodium hydroxide particles, uniformly mixing with a fine glass rod, covering the crucible cover, melting at the temperature of 750-850 ℃ for 10min, taking out, cooling, leaching the melt with a small amount of hot water and dilute nitric acid alternately, pouring into a 500ml beaker, and washing the crucible with a small amount of dilute nitric acid and water. The iron tailings solution was clarified by adding 20 ml of nitric acid to a 500ml beaker, and then filled into a 250 ml volumetric flask, and deionized water was added to the scale.

Hydrothermal method for preparing TiO₂/NaNiF₆Composite photocatalyst

0.4g of ammonium fluotitanate was added to a beaker, a small amount of deionized water was added, and the beaker was placed on a rotor and placed on a magnetic stirrer to melt it. And adding 20 ml of iron tailing solution into the other beaker, pouring the ammonium fluotitanate solution into the beaker containing the iron tailing solution, adding sodium hydroxide solution to adjust the pH value, adding a drop of solution when light yellow floccule appears, adjusting the pH value to 9, taking out the rotor, keeping the solution at 30 ml, adding deionized water to supplement the solution, and pouring the solution into a hydrothermal kettle. The hydrothermal kettle was then heated in a forced air drying oven at 190 ℃ for 12 hours.

Filtering, washing and suction-filtering the solution in the hydrothermal kettle for three times, using distilled deionized water for the first two times, using alcohol absolute ethyl alcohol for the last time, placing the obtained powder in a beaker, adding 100mL of deionized water, performing ultrasonic treatment for 4 hours, and then centrifuging; this was repeated three times and the powder was dried in a forced air oven at 70 ℃ for 10 h. Taking out after drying, grinding in a mortar, taking out and placing in a sealed bag.

Example 3

The early-stage treatment work comprises the following steps: drying the iron tailings at 105-110 ℃ for 2h, grinding, sieving with a 200-mesh sieve, burning the iron tailings at 850-900 ℃ for 3-4 min, and cooling for later use.

Preparing an iron tailing solution: accurately weighing about 0.5g of the treated iron tailing sand, placing the iron tailing sand in a nickel crucible, and firing the iron tailing sand for 3-5 min at the temperature of 850-900 ℃. Cooling the crucible, adding 4g of solid sodium hydroxide particles, uniformly mixing with a fine glass rod, covering the crucible cover, melting at the temperature of 750-850 ℃ for 10min, taking out, cooling, leaching the melt with a small amount of hot water and dilute nitric acid alternately, pouring into a 500ml beaker, and washing the crucible with a small amount of dilute nitric acid and water. The iron tailings solution was clarified by adding 20 ml of nitric acid to a 500ml beaker, and then filled into a 250 ml volumetric flask, and deionized water was added to the scale.

Hydrothermal method for preparing TiO₂/NaNiF₆Composite photocatalyst

0.5g of ammonium fluotitanate was added to a beaker, a small amount of deionized water was added, and the beaker was placed on a rotor and placed on a magnetic stirrer to melt it. And adding 20 ml of iron tailing solution into the other beaker, pouring the ammonium fluotitanate solution into the beaker containing the iron tailing solution, adding sodium hydroxide solution to adjust the pH value, starting adding one drop when light yellow floccules appear, adjusting the pH value to 8.5, taking out the rotor, keeping the solution at 30 ml, adding deionized water for supplementing, and pouring into a hydrothermal kettle. The hydrothermal kettle was then heated in a forced air drying oven at 170 ℃ for 11 hours.

Filtering, washing and suction-filtering the solution in the hydrothermal kettle for three times, using the deionized water for the first two times and using the absolute ethyl alcohol for the last time, putting the obtained powder in a beaker, adding 100mL of deionized water, performing ultrasonic treatment for 4 hours, and then centrifuging; this was repeated three times and the powder was dried in a forced air oven at 90 ℃ for 10 h. Taking out after drying, grinding in a mortar, taking out and placing in a sealed bag.

Performance testing

XRD (X-ray diffraction) testing is carried out on the powder prepared in the example 1, an XRD (X-ray diffraction) spectrum is shown in figure 1, and the prepared powder has stronger diffraction peaks, and the experimental data and a PDF standard card are compared to show that the powder has obvious diffraction peaks at the positions with 2 theta of 19.4 degrees, 19.95 degrees, 22.77 degrees, 32.4 degrees, 46.4 degrees and 58.4 degrees, which are respectively corresponding to NaNiF₆(Standard card PDF #22-1389) crystals of (011), (101), (002),And (312) a crystal plane; obvious diffraction peaks corresponding to TiO respectively at the positions of 25.2 degrees, 37.9 degrees, 48.14 degrees, 53.96 degrees, 55.05 degrees and 62.7 degrees of 2 theta₂(Standard card PDF #21-1272) crystal planes of (101), (004), (200), (105), (211) and (204); thus, the main crystal phase of the synthesized polycrystalline powder was anatase TiO₂And NaNiF₆The complex of (1).

Photocatalytic Performance detection

Adsorption test

The adsorption experiments were performed in a dark room. The method comprises the following specific operations: 0.05g of TiO was weighed out separately₂/NaNiF₆Measuring 15mL of rhodamine B solution in a quartz test tube, and then adding TiO into the quartz test tube₂/NaNiF₆Respectively placing the composite photocatalyst and titanium dioxide P25 into a quartz test tube filled with rhodamine B solution, simultaneously placing a magnetic rotor into the quartz test tube, then placing the quartz test tube into a photoreactor, opening magnetic stirring to perform darkroom adsorption reaction under the condition that a light source is not opened, taking samples every 5min, centrifuging to take supernatant liquid to perform absorbance value determination, analyzing the solution concentration change until the concentration does not change, namely the powder and the rhodamine B system reach adsorption and desorption balance.

As can be seen from the above table, the TiO prepared herein₂/NaNiF₆The adsorption rate of the composite photocatalyst is obviously superior to that of TiO₂P25。

Photocatalytic test

0.05g of TiO was weighed out separately₂/NaNiF₆Measuring 15mL of rhodamine B solution in a quartz test tube, and then adding TiO into the quartz test tube₂/NaNiF₆Respectively placing the composite photocatalyst and titanium dioxide P25 into a quartz test tube filled with a rhodamine B solution, simultaneously placing a magnetic rotor into the quartz test tube, then placing the quartz test tube into a photoreactor, carrying out dark reaction for 20min under the condition of not turning on a light source to enable the photocatalytic powder and the rhodamine B solution reaction system to reach adsorption/desorption balance, then turning on a mercury lamp light source, carrying out photodegradation on the rhodamine B solution, sampling once every 10min, centrifuging by using a centrifuge, taking supernatant, measuring absorbance after degradation by using an ultraviolet spectrophotometer, and calculating the concentration of the rhodamine B solution at different times. C is the concentration of rhodamine B solution during detection, C₀The concentration of the initial rhodamine B solution.

The results show that after 20min of illumination, the TiO of the present application is used₂/NaNiF₆The degradation rate of rhodamine B solution after the composite photocatalyst is 95 percent, which is superior to that of the commercially available TiO₂The degradation effect of P25 on rhodamine B under the same conditions is proved, and the degradation effect is proved by TiO₂/NaNiF₆The composite photocatalyst powder has stronger photocatalytic performance.